Study on the Suppression of Gyro-BWO by Distributed Wall Losses

In this paper, the effect of distributed wall losses on the starting length and starting frequency of a TE21 mode gyro-BWO is investigated for different operating magnetic fields by using a linear theory. Numerical results show that, for the efficient suppression of a gyro-BWO in a distributed wall losses gyro-TWA consisting of a lossy section followed by a copper section, the wall losses applied in the lossy section should be able to provide a cold attenuation approximately equal to the linear growth rate of the gyro-BWO in the case of wall losses neglected and the copper section length should be shorter than the starting length of the corresponding gyro-BWO without wall losses loaded.